1. Field of the Invention
The present invention generally relates to a method for synthesizing reaction products by use of an electrochemical cell, and more particularly to the use of a solid state cell to substantially enhance the rate of reaction during catalytic syntheses of reaction products such as hydrocarbons.
This invention was developed under grant DMR7724222 from National Science Foundation.
2. Description of the Prior Art
Solid electrolytes, primarily cationically conducting glasses and certain commercial ceramic materials, have been sporadically employed as passive components in electrochemical cells used to measure thermodynamic quantities over a period of many years. It has also been shown that one can use a solid state cell containing doped ZrO.sub.2 at elevated temperatures to measure the oxygen partial pressure in a gas over a very wide range.
Solid state electrochemical cells have also been employed in many laboratories as passive devices to measure a wide range of both thermodynamic and kinetic quantities. Devices utilizing these principles are being used in the exhaust systems of automobiles, and are being incorporated into most autos sold in California.
The active, as distinct from passive, use of such solid state ionic devices has also been developing. It has been shown in the laboratory that such systems can be used as oxygen pumps to produce extremely low oxygen activities in both static and flowing gases and liquids. Simple gases have also been decomposed (e.g. H.sub.2 O, CO, CO.sub.2) using this approach, with oxygen being separated from the other constituents at the gas-solid surface, and being transported away through the solid electrolyte, whereas the other elements remain in the gas stream. It has been shown that one can also decompose NO by the use of solid state ionics, and measurements have indicated that the specific reaction rate for the decomposition of NO on ZrO.sub.2 could be increased.
Meanwhile, there is an increasing need for new methods of producing fuels and many other chemicals from materials other than petroleum. One long known, alternate approach in the production of fuels is generally referred to as the Fischer-Tropsch synthesis reaction. This synthesis reaction utilizes hydrogen-deficient materials, such as coal, oil shale and tar sands, which are gasified with steam and oxygen to produce a gas containing CO and H.sub.2. After removal of contaminates, particularly sulphur-containing species, this gas can be catalytically converted to a variety of organic products. The hydrogenation of coal provided a substantial part of Germany's fuel during World War II.
However, the cost and efficiency of the prior known catalyst-controlled synthesis processes, and the number of complicating reactions, have posed serious practical problems. Some of the problems, for example, with the Fischer-Tropsch process are related to thermodynamic limitations, slow reaction kinetics, materials limitations (particularly the catalyst) and high cost of production.
In general, synthesis reactions, such as the known Fischer-Tropsch process, are much harder to control than decomposition reactions.